JP2004255423A - Laser cutting device, and laser cutting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser cutting device and a laser cutting method by which the detection of the cutting starting position of the edge part of the member to be cut and the control of the intervals between a laser head and the member to be cut in the cutting starting position can automatically and swiftly be performed. <P>SOLUTION: The laser cutting device is provided with a laser head 15, a detection means of detecting the intervals between the laser head 15 and the member W to be cut, and a control unit 16 of relatively moving the laser head 15 and the member W to be cut and controlling the intervals to a prescribed value based on the detected value from the detection means. In the control unit 16, when cutting is started from the edge part of the member W to be cut, at first, the intervals between the laser head 15 and the member W to be cut are controlled to a prescribed value on the member W to be cut, next, in a state where a laser is not applied and also in a state where the intervals are held to have the prescribed value, the laser head 15 is moved to a direction reverse to the cutting direction D along a cutting line CL, and when the detected value from the detection means is rapidly changed, the fact that the laser head 15 reaches the cutting starting position SP is judged: Then, with the intervals as intervals directly before the rapid change of the detected values from the detecting means, cutting is started from the cutting starting position SP. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser cutting device and a laser cutting method, and in particular, when starting cutting from an end of a member to be cut, detection of a cutting start position and a distance between a laser head and a member to be cut at the cutting start position. The present invention relates to a laser cutting apparatus and a laser cutting method capable of automatically and quickly performing adjustment.
[0002]
[Prior art]
A laser cutting device is known as a device for cutting a metal plate or the like along a predetermined cutting line.
[0003]
An example of a laser cutting device is shown in FIG.
[0004]
As shown in FIG. 5, the laser cutting device 10 holds a member W to be cut on the table 11 that is movable in the X-axis direction and a frame 12 that is provided so as to straddle the table 11. A carriage 13 movably mounted in the Y-axis direction, and a laser head 15 which is provided so as to be movable in the Z-axis direction with respect to the carriage 13 and irradiates a laser beam toward the member W to be cut. With. The control device 16 controls the movement of the table 11, the carriage 13, and the laser head 15 in the X, Y, and Z-axis directions, laser irradiation from the laser head 15, and the like. Such a laser cutting device 10 is also described in, for example, Patent Document 1.
[0005]
[Patent Document 1]
JP-A-9-136174 (FIG. 5 etc.)
[0006]
[Problems to be solved by the invention]
By the way, in this laser cutting apparatus 10, in order to obtain a high cutting accuracy and a good cut surface, the distance (Z-axis direction distance) between the laser head 15 and the member W to be cut is appropriately maintained. There is a need. The member to be cut W is not necessarily flat but may be curved (warped). In such a case, since the height (Z-axis direction position) of the member W to be cut differs depending on the part, it is necessary to cut the laser head 15 while adjusting the height appropriately.
[0007]
Therefore, conventionally, a height sensor (not shown) for detecting the distance between the laser head 15 and the member W to be cut is provided in the laser head 15, and the laser head 15 is moved up and down based on the detection value of the height sensor. The distance between the laser head 15 and the member W to be cut is always kept constant.
[0008]
The problem here is that, as shown in FIG. 6, when the cutting is started from the end SP of the member to be cut W, the distance between the laser head 15 and the member W to be cut at the end SP (laser head 15). (Height adjustment) is difficult. This is because the height sensor detects the distance between the laser head 15 and the table 11 at the end SP of the member W to be cut, and the laser head 15 may be aligned with the table 11. is there. If it does so, the laser head 15 will be too close with respect to the to-be-cut member W, and it will become impossible to cut | disconnect favorable.
[0009]
Therefore, conventionally, the operator adjusts the height of the laser head 15 to the cutting start position SP by visual observation. However, even with this method, since the adjustment is made by visual observation by the operator, high-precision adjustment is difficult and cannot be performed without the operator.
[0010]
As another method, a method as shown in FIG. 7 is also known. FIG. 7 is an enlarged view in the vicinity of the cutting start position SP. This method is based on the laser head based on the detection value of the height sensor at a certain point P1 on a portion (a scrap portion) of the member W to be cut. Adjust 15 heights. Then, the laser head 15 is moved along a predetermined cutting line CL to perform cutting to the cutting start position SP. In this method, the cutting start position SP is not a position at which cutting is started, but is referred to as a cutting start position together with FIG. 6 for convenience. Next, the height of the laser head 15 is adjusted again at a certain point P2 on the scrap portion of the member to be cut W, and this time, the cutting line CL is cut in the reverse direction. With this method, the height of the laser head 15 can be adjusted with high accuracy. However, this method requires two cutting operations to cut one cutting line CL, so that the efficiency is low and the manufacturing cost is high. In addition, since a notch or the like may be formed at the intersection part IP of the two cutting operations, the quality deteriorates. Or the operation | work which removes this notch is needed, and a manufacturing process and manufacturing cost rise.
[0011]
As yet another method, there is a method of detecting the X, Y, Z coordinates of the cutting start position SP using a touch probe and aligning the laser head 15 based on the detected value. Since it takes time to detect the cutting start position SP, the efficiency is poor and the manufacturing cost increases.
[0012]
Accordingly, an object of the present invention is to solve the above-described problems, and to detect the cutting start position and adjust the distance between the laser head and the member to be cut at the cutting start position when starting cutting from the end of the member to be cut. It is an object of the present invention to provide a laser cutting apparatus and a laser cutting method that can be executed automatically and quickly.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a laser head for irradiating a member to be cut with laser, detection means for detecting a distance between the laser head and the member to be cut, the laser head and the member to be cut. And a control device that adjusts the distance between the laser head and the member to be cut to a predetermined value based on the detection value of the detection means, the control device When cutting from the end of the member to be cut, first, the gap between the laser head and the member to be cut is adjusted to a predetermined value at an arbitrary position on the member to be cut, and then the laser In a state where the laser head is not irradiated and the distance between the laser head and the member to be cut is maintained at the predetermined value, the laser head is moved in a direction opposite to a predetermined cutting direction along a predetermined cutting line. And determining that the laser head has reached the cutting start position at the end of the member to be cut when the detection value of the detection means changes abruptly, and the interval between the laser head and the member to be cut Is the interval immediately before the detection value of the detection means suddenly changes, and the cutting is started from the cutting start position.
[0014]
Here, the control device does not adjust the interval between the laser head and the member to be cut based on the detection value of the detection means until the laser head cuts a predetermined distance from the cutting start position. May be.
[0015]
Further, the present invention provides a laser head and a member to be cut while adjusting the distance between the laser head and the member to be cut to a predetermined value based on a detection value of a detecting means for detecting a distance between the member to be cut and the laser head. A laser cutting method in which the distance between the laser head and the member to be cut is adjusted to the predetermined value at an arbitrary position on the member to be cut; The laser head is moved in a direction opposite to a predetermined cutting direction along a predetermined cutting line in a state where the laser head is not irradiated and the distance between the laser head and the member to be cut is maintained at the predetermined value. A step of determining that the laser head has reached the cutting start position at the end of the member to be cut when the detection value of the detection means changes abruptly; and the laser head And the distance between the target cutting member is obtained by a step of starting the cutting from the cutting start position as the last interval in which detection value changes sharply in the detection means.
[0016]
Here, it may further include a step of not performing the adjustment of the distance between the laser head and the member to be cut until the predetermined distance is cut from the cutting start position.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0018]
The schematic configuration of the laser cutting device of the present embodiment is the same as that shown in FIG. That is, the laser cutting device of the present embodiment holds the member W to be cut on the table 11 that is movable in the X-axis direction and the frame 12 provided so as to straddle the table 11. A carriage 13 attached so as to be movable in the axial direction, and a laser head 15 provided so as to be movable in the Z-axis direction with respect to the carriage 13 and irradiating a laser beam toward the member W to be cut. Prepare. The control device controls the movement of the table 11, the carriage 13, and the laser head 15 in the X, Y, and Z-axis directions (that is, relative movement between the laser head 15 and the member W to be cut), laser irradiation from the laser head 15, and the like. 16 is controlled.
[0019]
Although not shown, the laser cutting device of the present embodiment further includes a height sensor (detection means) that is provided in the laser head 15 and detects the distance (Z-axis direction distance) between the laser head 15 and the member W to be cut. . In this embodiment, the height sensor is a capacitance sensor capable of measuring with relatively high sensitivity. The detection value of the capacitance sensor is input to the control device 16.
[0020]
The X and Y coordinates of a predetermined cutting line CL (see FIG. 2) are input to the control device 16 in advance, and the laser head 15 moves in advance along the cutting line CL with respect to the member W to be cut during the cutting operation. The carriage 13 and the table 11 are moved so as to move relative to the determined cutting direction D. The control device 16 basically moves the laser head 15 in the Z-axis direction as appropriate based on the detection value of the height sensor while moving the laser head 15 along the cutting line CL. The distance from the member to be cut W is kept constant.
[0021]
Now, as shown in FIG. 2, the laser cutting device of this embodiment detects the cutting start position SP and starts the cutting start position when starting cutting from the cutting start position SP at the end of the member W to be cut. The distance between the laser head 15 and the member W to be cut in SP can be automatically and quickly adjusted, and this point will be described below.
[0022]
FIG. 1 is a flowchart of the cutting start control executed by the control device 16, and the cutting method by the laser cutting device of the present embodiment will be described based on this flowchart and FIG.
[0023]
First, in step S1, the carriage 13 and the table 11 are moved so that the laser head 15 is positioned at the measurement point MP on the cutting line CL of the member W to be cut. The measurement point MP can be set at an arbitrary position on the cutting line CL, and its X and Y coordinates are input to the control device 16 in advance.
[0024]
Next, in step S2, the height sensor is driven (ON), and in step S3, the distance between the laser head 15 and the member to be cut W is measured.
[0025]
In step S4, it is determined whether or not the interval measured in step S3 is equal to the set interval input to the control device 16 in advance. The setting interval is set to a value necessary for obtaining a good cutting. It should be noted that a predetermined allowable error (for example, about ± 0.00 mm) may be provided in the set interval.
[0026]
If the measurement interval is not equal to the set interval, the laser head 15 is moved in a direction to reduce the difference, and the process returns to step S2 to continue the interval measurement by the height sensor.
[0027]
That is, in steps S2 to S4, height adjustment of the laser head 15 at the measurement point MP (adjustment of the distance between the laser head 15 and the member W to be cut) is performed.
[0028]
If it is determined in step S4 that the measurement interval is equal to the set interval, the process proceeds to step S5, and the carriage 13 is moved so that the laser head 15 moves in the direction opposite to the predetermined cutting direction D along the cutting line CL. And the table 11 is moved. At this time, no laser is irradiated from the laser head 15, and the member W to be cut is not cut.
[0029]
While the laser head 15 moves in the reverse direction along the cutting line CL, in step S6, the change amount V of the detection value of the height sensor is always calculated, and in step S7, the change amount V is greater than a predetermined threshold value T. It is determined whether or not it is larger. The threshold value T is a value that can be considered that the detection value of the height sensor has changed rapidly, and is input to the control device 16 in advance.
[0030]
If it is determined that the change amount V is equal to or less than the threshold value T, the process returns to step S2, and the interval between the laser head 15 and the member W to be cut becomes the set interval, that is, the change amount V is eliminated. The laser head 15 is moved. In short, while the laser head 15 moves in the direction opposite to the cutting direction D along the cutting line CL, the height of the laser head 15 is adjusted based on the detection value from the height sensor, and the laser head 15 and the member W to be cut W. The interval between and is maintained at the set interval.
[0031]
On the other hand, when it is determined in step S7 that the change amount V is larger than the threshold value T, the process proceeds to step S8, the movement of the carriage 13 and the table 11 is stopped, and the movement of the laser head 15 relative to the member W to be cut is performed. Stop. That the change amount V is larger than the threshold value T means that the detection value of the height sensor has changed abruptly, and that the laser head 15 has reached the cutting start position SP of the member W to be cut. I mean. That is, the change in height due to the warp of the member to be cut W is not abrupt, but continuously changes. Therefore, when the detection value of the height sensor changes abruptly, the laser head 15 moves the member W to be cut. It can be determined that the height sensor has detected the distance between the laser head 15 and the table 11 by reaching the end SP.
[0032]
When it is determined in step S7 that the change amount V is larger than the threshold value T, the height of the laser head 15 is maintained at a position immediately before the change amount V exceeds the threshold value T. That is, when the change amount V exceeds the threshold value T, the height adjustment of the laser head 15 is not performed. Accordingly, the laser head 15 is positioned at a height that is separated from the cutting start position SP of the member W by a set interval.
[0033]
Next, proceeding to step S9, the carriage 13 and the table 11 are moved so that the laser head 15 moves in the cutting direction D along the cutting line CL. In step S10, the laser head 15 irradiates a laser to be cut. The cutting of the member W is started. At the start of cutting, the laser head 15 is naturally adjusted to a height suitable for the cutting start position SP of the member W to be cut. After the start of cutting, the laser head 15 is appropriately moved up and down based on the detection value from the height sensor, and the interval between the laser head 15 and the member W to be cut is maintained at the set interval.
[0034]
Thus, according to the laser cutting device and the laser cutting method of the present embodiment, the detection of the cutting start position SP at the end of the member to be cut W, and the laser head 15 and the member to be cut W at the cutting start position SP are performed. The interval adjustment can be performed automatically and quickly. Therefore, good cutting can be performed at low cost.
[0035]
Next, another embodiment of the present invention will be described.
[0036]
This form is suitable when the width L1 of the member W to be cut is slightly larger than the width L2 as a product, as shown in FIG. In this case, since the cutting with high accuracy is not required until the laser head 15 moves from the cutting start position SP by the distance L3, the height adjustment of the laser head 15 based on the detection value of the height sensor is executed during that time. This is what I did not.
[0037]
The cutting method of this embodiment is demonstrated using the flowchart of FIG.
[0038]
Steps S101 to S104 are the same as steps S1 to S4 in FIG.
[0039]
If it is determined in step S104 that the interval between the laser head 15 and the member W to be cut at the measurement point MP is equal to the set interval, the process proceeds to step S105 and the height sensor is disabled (OFF). In this embodiment, the measurement point MP is set at a position on the inner side by the distance L3 from the cutting start position SP of the member W to be cut. The height of the laser head 15 is adjusted at the measurement point MP, and the height sensor is invalidated at that position.
[0040]
In step S106, the carriage 13 and the table 11 are moved so that the laser head 15 moves in the direction opposite to the cutting direction D along the cutting line CL, and the member to be cut is the same as in the embodiment of FIG. The cutting start position SP at the end of W is detected. In step S107, the carriage 13 and the table 11 are moved so that the laser head 15 moves in the cutting direction D along the cutting line CL, and the laser W is irradiated with the laser to cut the member W to be cut. To start. At this time, the height sensor remains invalid and the height adjustment of the laser head 15 is not executed.
[0041]
When the laser head 15 moves along the cutting line CL by the distance L3 and reaches the point MP, the process proceeds to step S108, and the height sensor is enabled (ON). Next, it progresses to step S109 and the cutting | disconnection along the cutting line CL is continued. At this time, since the height sensor is effective, the height adjustment of the laser head 15 is executed based on the detection value of the height sensor while cutting after the point MP. On the cutting end side of the cutting line CL, when the point MP ′ that is inward by the distance L3 from the cutting end position EP is reached, the height sensor is invalidated again and thereafter (that is, from the point MP ′ to the point EP). The height adjustment of the laser head 15 may not be executed during the interval).
[0042]
According to this embodiment, since the distance between the laser head 15 and the member to be cut W is not adjusted in a portion that does not require high-precision cutting, the working time can be shortened.
[0043]
It should be noted that both the program for executing the control shown in FIG. 1 and the program for executing the control shown in FIG. 4 are input to the control device 16 and executed in accordance with the state of the member W to be cut. May be selected.
[0044]
The present invention is not limited to the laser cutting apparatus as shown in FIG. 5, and can be applied to various types of laser cutting apparatuses. For example, a type in which the table 11 can move in the X axis and the Y axis and a type in which the laser head 15 can move in the X, Y, and Z axis directions are naturally applicable.
[0045]
The height sensor is not limited to a capacitance sensor, and any type can be applied as long as the distance between the laser head 15 and the member to be cut W can be detected.
[0046]
Furthermore, in the above embodiment, the measurement point MP for adjusting the distance between the laser head 15 and the member to be cut W is first set on the cutting line CL, but this is not always necessary. That is, after adjusting the interval at an arbitrary point on the member to be cut W, the laser head 15 may be positioned on the cutting line CL and then moved along the cutting line CL.
[0047]
【The invention's effect】
In short, according to the present invention, the excellent effect that the detection of the cutting start position at the end of the member to be cut and the adjustment of the distance between the laser head and the member to be cut at the cutting start position can be executed automatically and quickly. It is something that demonstrates.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a cutting method according to an embodiment of the present invention.
FIG. 2 is a view for explaining the cutting method of the embodiment of FIG. 1, showing a member to be cut and its cutting line.
FIG. 3 is a view for explaining a cutting method according to another embodiment of the present invention, and shows a member to be cut and its cutting line.
FIG. 4 is a flowchart showing a cutting method according to another embodiment of the present invention.
FIG. 5 is a perspective view of a laser cutting device.
FIG. 6 is a diagram for explaining a case where cutting is started from an end of the member to be cut, and shows the member to be cut and its cutting line.
FIG. 7 is a diagram for explaining a conventional cutting method, and is an enlarged view in the vicinity of a cutting start position.
[Explanation of symbols]
10 Laser Cutting Device 11 Table 13 Carriage 15 Laser Head 16 Control Device SP Cutting Start Position W Member to be Cut

Claims (4)

A laser head for irradiating a member to be cut with laser; a detecting means for detecting a distance between the laser head and the member to be cut; and a means for moving the laser head and the member to be cut relative to each other, and the detecting means. A laser cutting device comprising a control device for adjusting a distance between the laser head and the member to be cut to a predetermined value based on a detected value of
When starting the cutting from the end of the member to be cut, the control device first adjusts the interval between the laser head and the member to be cut to a predetermined value at an arbitrary position on the member to be cut. In addition, the laser head is opposite to a predetermined cutting direction along a predetermined cutting line in a state where the laser is not irradiated and the distance between the laser head and the member to be cut is maintained at the predetermined value. When the detected value of the detection means changes suddenly, it is determined that the laser head has reached the cutting start position at the end of the member to be cut, and the laser head, the member to be cut, The laser cutting device is characterized in that the cutting is started from the cutting start position with the interval immediately before the detection value of the detecting means changes abruptly. 2. The control device according to claim 1, wherein the controller does not adjust the distance between the laser head and the member to be cut based on a detection value of the detection unit until the laser head cuts a predetermined distance from the cutting start position. Laser cutting device. Based on the detection value of the detecting means for detecting the distance between the member to be cut and the laser head, the distance between the laser head and the member to be cut is adjusted to a predetermined value, and the laser head and the member to be cut are relatively moved. A laser cutting method of moving and cutting,
Adjusting the interval between the laser head and the member to be cut to the predetermined value at an arbitrary position on the member to be cut;
In a state in which the laser head is not irradiated and the distance between the laser head and the member to be cut is maintained at the predetermined value, the laser head is moved in a direction opposite to a predetermined cutting direction along a predetermined cutting line. A moving step;
Determining that the laser head has reached the cutting start position at the end of the member to be cut when the detection value of the detection means changes abruptly;
And a step of starting cutting from the cutting start position with the interval between the laser head and the member to be cut as the interval immediately before the detection value of the detecting means changes abruptly. The laser cutting method according to claim 3, further comprising a step of not performing an adjustment of a distance between the laser head and the member to be cut until the predetermined distance is cut from the cutting start position.

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